The Devils is a 1971 historical psychological horror-drama film written, produced and directed by Ken Russell, and starring Vanessa Redgrave and Oliver Reed. A dramatised historical account of the fall of Urbain Grandier, a 17th-century Roman Catholic priest accused of witchcraft after the possessions in Loudun, France, the plot also focuses on Sister Jeanne des Anges, a sexually repressed nun who incites the accusations.

A co-production between the United Kingdom and the United States, The Devils is in part adapted from the 1952 non-fiction book The Devils of Loudun by Aldous Huxley, as well as John Whiting's subsequent 1960 play The Devils. United Artists initially pitched the idea to Russell but bowed out after reading his finished screenplay, as they felt it was too controversial in nature. Warner Bros. agreed to produce and distribute, and filming largely took place at Pinewood Studios in late 1970.

The film's graphic portrayal of violent and sexual content, often combined with religion, ignited harsh reaction from censors, and it originally received an X rating in both the United Kingdom and the United States. It was banned in several countries, and heavily edited for exhibition in others. Although critics largely dismissed the film for its explicit content, it won awards for Best Director at the 33rd Venice International Film Festival, as well as from the U.S. National Board of Review. Although a restoration of Russell's director's cut of The Devils was given its first theatrical release in the UK in 2002, this version has not been made officially available on home media, and releases of edited versions of the film on DVD and streaming services remain scant.

Film scholarship primarily focuses on themes of sexual repression and political corruption. The Devils has been recognized as one of the most controversial films of all time by numerous publications and critics, and remained banned in Finland until 2001.